CN103033133A - Method for acquiring oscillatory boundary of jet in cross-flow of liquid - Google Patents
Method for acquiring oscillatory boundary of jet in cross-flow of liquid Download PDFInfo
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- CN103033133A CN103033133A CN2012105956629A CN201210595662A CN103033133A CN 103033133 A CN103033133 A CN 103033133A CN 2012105956629 A CN2012105956629 A CN 2012105956629A CN 201210595662 A CN201210595662 A CN 201210595662A CN 103033133 A CN103033133 A CN 103033133A
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Abstract
The invention relates to a method for acquiring the oscillatory boundary of jet in cross-flow of liquid. The method comprises the following steps: 1, obtaining a scale in an observation plane through a high-speed shooting method, shooting liquid jet in a gas flow field, and obtaining a group of serial digital image results of the jet in the flow field; 2, counting the grey scale values of pixels on each collection line in N images; 3, acquiring probability distribution of corresponding grey scale of each pixel and the probability maximum of grey scale of each pixel; 4, acquiring the boundary points which oscillate the most violently on the collection line; 5, seeking the boundary points which oscillate the most violently on all the collection lines; and 6, connecting the boundary points which oscillate the most violently on all the collection lines to obtain the boundary line of jet, wherein a physical boundary line is obtained according to the scale measured in step 1, According to the invention, the boundary of liquid jet is obtained by measuring the most violent oscillatory boundary of liquid jet in airflow; and the measuring method does not concern anthropic factors, and the measurement result is objective, quantitative and sole.
Description
Technical field
The present invention relates to optical measuring technique and image processing field, particularly relate to a kind of acquisition methods based on the thermal agitation border of liquid transverse jet in the unsteady flow field of high-speed photography.
Background technology
In the engine take liquid fuel as propellant, the spray of liquid transverse jet and atomizing are very important processes.When the spray of studying transverse jet and atomization characteristics, the boundary information of jet is a very important measurement parameter, it has affected the blending degree of fogging degree and jet and the air-flow of liquid transverse jet, and has determined the spreading range of liquid transverse jet main flow.For the research on liquid transverse jet border, the method that in the past usually adopted has: the corresponding image processing techniques of PDPA method, sheet light method, High Speed Photography, shadowing method, schlieren method etc. and combination, and to obtain the corresponding jet boundary information of each method.
The PDPA method adopts the mode of one-point measurement, can obtain the local volume flow rate of the drop of jet crushing formation, and obtains the peripheral boundary of jet according to the definition of different jet boundaries.Document " Lin K C; Kennedy P J; Jackson TA.Structures of water jets in a Mach 1.94supersonic crossflow.2004; AIAA-2004-971 " and " Wu P K; Kirkendall K A, Fuller R P, et al.Spray structure of liquid j ets atomized in subsonic crossflow[J] .Journal of Propulsion and Power; 1998,14 (2); 173-182 " volume flow rate that jet peripheral boundary point in the air-flow is defined as jet is 0.01cc/ (scm
2) or 0.02cc/ (scm
2) point, both are not too identical for the definition of liquid mist periphery; Simultaneously the PDPA method is taked is that single-point in the stream field is measured, the jet boundary information that its efficient is lower, be difficult to the whole flow field of disposable acquisition.
For sheet light method and corresponding image processing techniques, document " Chaouki Ghenai; Hayri Sapmaz; Cheng-Xian Lin.Penetration height correlation for non-aerated and aerated transverse liquid jets in supersonic cross flow; Exp Fluids; 2009,49:121-129 " is processed the digital picture that adopts sheet light method to obtain in conjunction with the Canny method, has obtained the border of jet.But its border that obtains is the border on the image processing meaning, without clear and definite physical significance; Simultaneously its in the Canny method shade of gray threshold value choose result's impact greatlyr, different threshold value gained jet boundaries differ larger, human factor is larger in the Digital Image Processing process, acquired results is not unique.
High Speed Photography, shadowing method and schlieren method can both obtain the general profile of jet main flow, document " Lai Lin. the flow field test of the super burn engine of band cavity firing chamber and simulation study [D]. Changsha: the .2003 of the National University of Defense Technology " point out to adopt identical measuring method to use different digital image processing techniques, the result who obtains is not quite similar.Jet boundary information to obtaining based on the image processing techniques of high-speed photography acquired results all was the border on image is processed in the past, and physical significance is indefinite, and human factor is larger in the processing procedure, can not obtain the result of unique quantification.
Document " J.Beloki Perurena; C.O.Asma; R.Theunissen; O.Chazot.Experimental investigation of liquid jet injection into Mach 6 hypersonic crossflow.Exp Fluids; 2009; 46:4.3-417 " has proposed a kind of method of definite jet boundary approximate location of the gray probability based on high-speed photography gained image, but it does not obtain the result of quantification, has just described the approximate location of jet boundary.
As a whole, at present more for definition and the acquisition methods of hydrofluidic penetration depth in the supersonic flow, but the corresponding digital image processing method of some method is mainly measured jet outermost border, some results' physical significance is not too clear and definite, human factor is larger in the image processing process, the result who obtains quantification that can not be unique.For hydrofluidic border in the supersonic flow be badly in need of a kind of energy well-determined, fast, border quantification, explicit physical meaning acquisition methods.
Summary of the invention
For above-mentioned present situation, the acquisition methods that the purpose of this invention is to provide a kind of liquid transverse jet oscillating edge movement, based on High Speed Photography, image processing techniques and mathematical statistics method, by measuring in the air-flow the thermal agitation border of liquid hydrofluidic, the border that obtains hydrofluidic.Measuring method does not relate to human factor, and measurement result is objective, quantitative, unique.
The acquisition methods of a kind of liquid transverse jet of the present invention oscillating edge movement may further comprise the steps:
(1), utilize high-speed photographing method at first to obtain scale in the plane of vision, then the hydrofluidic in the gas flowfield is taken, obtain the one group continuous digital picture result of jet in the flow field;
(2), respectively gather line epigraph gray-scale value in the statistics N width of cloth image;
Take jet spray point as initial point, take the gas velocity direction as x axle positive dirction, take the jet injection direction as y axle positive dirction, take initial point as starting point, the positive dirction of x axle, take the k pixel distance as step-length, as a collection line, add up and obtain the corresponding gray-scale value of all pixels on this line;
(3), obtain the probability distribution of each pixel corresponding grey scale and the maximum probability value of each pixel gray scale;
Each gray scale occurs in the statistics N width of cloth image frequency n _ p and acquisition probability f_p=n_p/N, wherein p represents certain gray-scale value, relatively and obtain this to put maximum probability value corresponding to all gray-scale values be f
Max=max (f_p);
(4), obtain the most violent frontier point of vibration;
Obtain the maximal value that gathers the gray probability that all pixels are corresponding on the line, obtain gathering f corresponding on the line
Max-y graph of a relation picture, its minimum point is the most violent frontier point of vibration.
(5), search all and gather the most violent frontier point of liquid transverse jet vibration on lines;
(6), all the most violent frontier points of vibration that gather on lines are coupled together, obtain the boundary line of jet, the scale measured according to step 1 obtains the physical boundary line.
Because the present invention adopts high-speed photography that whole flow field is observed, therefore the present invention is more simpler, quick than the single-spot way of PDPA; Simultaneously since among the present invention image processing method unmanned be the step of selected threshold, therefore affect littlely with respect to High Speed Photography, shadowing method, the resulting as a result human factor of schlieren method, can obtain unique, objective, quantitative result; The present invention combines the oscillating characteristic of jet in addition, and is clearer and more definite than the image processing method physical significance in other High Speed Photographies, shadowing method, schlieren method and the sheet light method.
Description of drawings
The a part of accompanying drawing that consists of the application is used to provide a further understanding of the present invention, and illustrative example of the present invention and explanation thereof are used for explaining the present invention, do not consist of improper restriction of the present invention.In the accompanying drawings:
Fig. 1: process flow diagram of the present invention
Fig. 2: high-speed photography system structural drawing of the present invention
Fig. 3: graphical analysis coordinate system, the line of observation and observation station
Fig. 4: observation station gray scale-probability graph
Fig. 5: line of observation position-gray scale maximum probability figure
Fig. 6: processing result image
Embodiment
The acquisition methods of a kind of liquid transverse jet of the present invention oscillating edge movement with reference to Fig. 1, specifically may further comprise the steps:
(1), utilize high-speed photographing method at first to obtain scale in the plane of vision, then the hydrofluidic in the gas flowfield is taken, obtain the one group continuous digital picture result of jet in the flow field;
Referring to accompanying drawing 2, stable light source 1 is arranged in a side of test section jet 7, opposite side is arranged high-speed camera 5, the position, optical center of light source 1 center, jet 4 centers, high-speed photography camera 5 is positioned on the same vertical height.Then carry out the focusing of high-speed photography camera 5, make the focal plane 2 of camera 5 parallel with air-flow 3 directions and hydrofluidic 4 directions, the focal plane 2 of camera 5 be positioned at the jet nozzle center and with light source 1 plane parallel.Regulate light source 1 intensity, reduce high-speed photography camera 5 time shutter, improve photographed frame speed and bust shot zone 2, guarantee to obtain image clearly and satisfy the requirement of photographed frame speed.Then, scale information is taken and preserved to the 2 interior placement scales in the camera focal plane.After camera and light source are regulated and are finished, keep camera and the intensity of light source constant, in the flow field, pass into gas 3 and liquid transverse jet 4, jet 4 by the effect of air-flow 3 bend, broken and atomizing forms droplet, utilize high-speed camera that jet 4 and drop are carried out the high-speed photography shooting, obtain the one group continuous digital picture result of jet in the flow field.
(2), respectively gather line epigraph gray-scale value in the statistics N width of cloth image;
As shown in Figure 3, the present embodiment is take jet spray point as initial point, take the gas velocity direction as x axle positive dirction, take the jet injection direction as y axle positive dirction, take initial point as starting point, along the positive dirction of x axle, take per 10 pixel distances as step-length, as a collection line, add up and obtain the corresponding gray-scale value of all pixels on this line.Collection line among Fig. 3 is the collection line of the 30th step-length.The number of high-speed photography photographic images when N is the jet spray, N is the bigger the better, but N can affect the sharpness that high-speed photography is taken.
(3), obtain the probability distribution of each pixel corresponding grey scale and the maximum probability value of each pixel gray scale;
Referring to shown in Figure 3, for example get the Points on Straight Line (300 of x=300,100) as analysis site, because the vibration of jet and the vibration in flow field, the gray-scale value that pixel (300,100) is corresponding in N width of cloth image can constantly change, and adds up the frequency n _ p (wherein p represents certain gray-scale value) of each gray scale appearance and obtains probability f_p=n_p/N corresponding to this gray scale, for example pixel (300,100) corresponding grey scale value is 30 probability f_30=n_30/N; Referring to Fig. 4, obtain this and put probability corresponding to all gray-scale values (p=0～255), and the maximal value of asking in the corresponding probability of all gray scales is f
Max=max (f_p).
(4), obtain the most violent frontier point of vibration;
According to the method in the step 3, referring to Fig. 5, obtain the maximal value of the gray probability that all pixels are corresponding on the x=300 straight line, can obtain f corresponding on the x=300 straight line
Max-y graph of a relation picture is determined f
MaxMinimum point in the-y image, i.e. f
MaxMinimum point; Because the frontier point place corresponding pixel points gray-scale value dispersion maximum that fluidic oscillation is the most violent, the probability that each gray-scale value occurs is all less, therefore f
MaxThe minimum point of value is jet at the most violent frontier point of x=300 position vibration.
(5), search all and gather the most violent frontier point of vibration on lines;
Search all x=10m (m=1,2,3 in the image according to step 3 and four method ...) the most violent frontier point of fluidic oscillation on the straight line, the oscillating edge movement of the jet that acquired results namely obtains.
(6), all the most violent frontier points of vibration that gather on lines are coupled together, obtain the boundary line of jet, the scale measured according to step 1 obtains the physical boundary line.
Referring to Fig. 6, the divergent boundary point that obtains in the step (five) is linked to each other, the scale in conjunction with gained in () is converted to the actual physics space length with pixel distance, thereby obtains the boundary line of jet.
Various not illustrating the restriction of essence of an invention Composition of contents, the person of an ordinary skill in the technical field after having read instructions can to before described embodiment make an amendment or be out of shape, do not deviate from essence of an invention and scope.
Claims (1)
1. the acquisition methods of a liquid transverse jet oscillating edge movement may further comprise the steps:
(1), utilize high-speed photographing method at first to obtain scale in the plane of vision, then the hydrofluidic in the gas flowfield is taken, obtain the one group continuous digital picture result of jet in the flow field;
(2), respectively gather line epigraph gray-scale value in the statistics N width of cloth image;
Take jet spray point as initial point, take the gas velocity direction as x axle positive dirction, take the jet injection direction as y axle positive dirction, take initial point as starting point, along the positive dirction of x axle, take every k pixel distance as step-length, gather line as one, add up and obtain in the N width of cloth image the corresponding gray-scale value of all pixels on this line;
(3), obtain the probability distribution of each pixel corresponding grey scale and the maximum probability value of each pixel gray scale;
Frequency n _ p that each gray scale occurs in the statistics N width of cloth image also obtains general f_p=n_p/N, and wherein p represents certain gray-scale value, relatively and obtain this to put maximum probability value corresponding to all gray-scale values be f
Max=max (f_p);
(4), obtain the most violent frontier point of vibration;
Obtain the maximal value that gathers the gray probability that all pixels are corresponding on the line, obtain gathering f corresponding on the line
Max-y graph of a relation picture, its minimum point is the most violent frontier point of vibration;
(5), search all and gather the most violent frontier point of vibration on lines;
(6), all the most violent frontier points of vibration that gather on lines are coupled together, obtain the boundary line of jet, the scale measured according to step 1 obtains the physical boundary line.
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104501737A (en) * | 2014-12-19 | 2015-04-08 | 中国人民解放军国防科学技术大学 | Device and method for positioning boundary of liquid jet spray |
| CN104569482A (en) * | 2014-12-31 | 2015-04-29 | 江苏大学 | Surface speed measurement device and method for high-speed liquid jet |
| CN104634279A (en) * | 2013-11-13 | 2015-05-20 | 中国科学院沈阳计算技术研究所有限公司 | Vision-based automatic aviation oil mist nozzle atomization angle detection device and method |
| CN105547185A (en) * | 2016-01-15 | 2016-05-04 | 中国人民解放军国防科学技术大学 | Method for obtaining lateral jet boundary of liquid |
| CN106678791A (en) * | 2017-03-07 | 2017-05-17 | 中国人民解放军国防科学技术大学 | Liquid fuel injection device used for increasing jet flow penetration depth |
| CN113139941A (en) * | 2021-04-21 | 2021-07-20 | 北京工业大学 | Method for judging whether gas jet blows out flame |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101170641A (en) * | 2007-12-05 | 2008-04-30 | 北京航空航天大学 | A method for image edge detection based on threshold sectioning |
| WO2009005011A1 (en) * | 2007-06-29 | 2009-01-08 | Seiko Epson Corporation | Liquid attribute detecting device, liquid container, image forming device, and liquid attribute detecting method |
| CN101819026A (en) * | 2010-04-22 | 2010-09-01 | 江苏大学 | Method for measuring ultrahigh-pressure water jet length and radius for water cutting |
-
2012
- 2012-12-31 CN CN201210595662.9A patent/CN103033133B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2009005011A1 (en) * | 2007-06-29 | 2009-01-08 | Seiko Epson Corporation | Liquid attribute detecting device, liquid container, image forming device, and liquid attribute detecting method |
| CN101170641A (en) * | 2007-12-05 | 2008-04-30 | 北京航空航天大学 | A method for image edge detection based on threshold sectioning |
| CN101819026A (en) * | 2010-04-22 | 2010-09-01 | 江苏大学 | Method for measuring ultrahigh-pressure water jet length and radius for water cutting |
Non-Patent Citations (6)
| Title |
|---|
| CHAOUKI GHENAI等: "Penetration height correlations for non-aerated and aerated transverse liquid jets in supersonic cross flow", 《EXPERIMENTS IN FLUIDS》 * |
| J.BELOKI PERURENA等: "Experimental investigation of liquid jet injection into Mach 6 hypersonic crossflow", 《EXPERIMENTS IN FLUIDS》 * |
| PEI-KUAN WU等: "Spray Structures of Liquid Jets Atomized in Subsoni", 《JOURNAL OF PROPULSION AND POWER》 * |
| THOMAS RH等: "Distributions across the plume of transverse liquid and slurry jets in supersonic crossflow", 《AIAA JOURNAL》 * |
| 刘静等: "高速气流中横向液体射流雾化研究进展", 《力学进展》 * |
| 吕为等: "新型双出口合成射流激励器的流场特征研究", 《实验流体力学》 * |
Cited By (9)
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| CN104634279A (en) * | 2013-11-13 | 2015-05-20 | 中国科学院沈阳计算技术研究所有限公司 | Vision-based automatic aviation oil mist nozzle atomization angle detection device and method |
| CN104501737A (en) * | 2014-12-19 | 2015-04-08 | 中国人民解放军国防科学技术大学 | Device and method for positioning boundary of liquid jet spray |
| CN104569482A (en) * | 2014-12-31 | 2015-04-29 | 江苏大学 | Surface speed measurement device and method for high-speed liquid jet |
| CN104569482B (en) * | 2014-12-31 | 2018-01-16 | 江苏大学 | A kind of high-velocity liquid jet superficial velocity measurement apparatus and method |
| CN105547185A (en) * | 2016-01-15 | 2016-05-04 | 中国人民解放军国防科学技术大学 | Method for obtaining lateral jet boundary of liquid |
| CN105547185B (en) * | 2016-01-15 | 2018-03-09 | 中国人民解放军国防科学技术大学 | The acquisition methods on liquid transverse jet border |
| CN106678791A (en) * | 2017-03-07 | 2017-05-17 | 中国人民解放军国防科学技术大学 | Liquid fuel injection device used for increasing jet flow penetration depth |
| CN106678791B (en) * | 2017-03-07 | 2019-04-16 | 中国人民解放军国防科学技术大学 | For improving the liquid fuel injection device of jet penetration |
| CN113139941A (en) * | 2021-04-21 | 2021-07-20 | 北京工业大学 | Method for judging whether gas jet blows out flame |
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